2002 YAMAHA YFM660R heating

6-23
EBU00209
Engine break-in
There is never a more important period in the life of
your machine than the period between zero and
20 hours.
For this reason, we ask that you carefully read the
following material. Because the engine is brand
new, you must not put an excessive load on it for
the first several hours of running. During the first
20 hours, the various parts in the engine wear and
polish themselves to the correct operating clear-
ances.
During this period, prolonged full throttle operation
or any condition which might result in excessive
engine heating must be avoided. However, mo-
mentary (2 ~ 3 seconds maximum) full throttle op-
eration under load does not harm the engine.
Each full throttle acceleration sequence should be
followed with a substantial rest period for the en-
gine by cruising at lower r/min so the engine can
rid itself of the temporary build up of heat.
If any abnormality is noticed during this period,
consult a Yamaha dealer.
U5LP61.book Page 23 Monday, August 27, 2001 3:49 PM

8-49 1. Hose
1. Flexible
1. Manguera
NOTE:The air filter element should be cleaned every
20 ~ 40 hours. It should be cleaned and lubricated
more often if the machine is operated in extremely
dusty areas. Each time the filter element mainte-
nance is performed, check the air inlet to the filter
case for obstructions. Check the air cleaner rubber
joint to the carburetor and manifold fittings for an
airtight seal. Tighten all fittings securely to avoid
the possibility of unfiltered air entering the engine. CAUTION:
Never operate the engine with the air filter ele-
ment removed. This will allow unfiltered air to
enter, causing rapid engine wear and possible
engine damage. Additionally, operation with-
out the filter element will affect carburetor jet-
ting with subsequent poor performance and
possible engine overheating.
U5LP61.book Page 49 Monday, August 27, 2001 3:49 PM

8-122
Engine overheatingNOTE:If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible.
WARNING
Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. Wait until the
engine has cooled.
Check the coolant level in the
reservoir tank and/or radiator.
Level is OK.Level is low, check the
cooling system for leakage.
No
leakage.Leakage.
Ask a Yamaha dealer to inspect
and repair the cooling system.Add coolant. (See NOTE.)
Restart the engine. If the engine overheats again, ask a
Yamaha dealer to inspect and/or repair the cooling system.
U5LP61.book Page 122 Monday, August 27, 2001 3:49 PM